My U.S. Pat. No. 5,482,441, issued Jan. 9, 1996, discloses a system which can be utilized to desalinate sea water. There are, of course, many prior art systems which utilize reverse osmosis to accomplish such objective. Typically, prior art desalinization systems are very expensive to operate and difficult to service. The system of my above-referenced patent addresses this problem.
The apparatus disclosed and claimed herein represents another approach to solving the problems inherent in the prior art and has certain features in common with the invention disclosed in my U.S. Pat. No. 5,462,414 including use of a reversible piston which cooperates with filter means to produce desalinated water.
While reversible pistons per se are employed in prior art hydraulic circuits generally, the structural combination of a reversible piston and other related mechanism employed in the present filtering system differs in regard to both structure and manner of operation. U.S. Pat. No. 4,793,153, issued Dec. 27, 1988 discloses a typical prior art hydraulic circuit employing a reversible piston to accomplish "energy recovery" in a mixed-phase motor in a refrigeration system.